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. 2022 Jul 1;29(Pt 4):939-946.
doi: 10.1107/S1600577522005720. Epub 2022 Jun 8.

Shot-to-shot two-dimensional photon intensity diagnostics within megahertz pulse-trains at the European XFEL

Trey W Guest  1 , Richard Bean  2 , Johan Bielecki  2 , Sarlota Birnsteinova  2 , Gianluca Geloni  2 , Marc Guetg  3 , Raimund Kammering  3 , Henry J Kirkwood  2 , Andreas Koch  2 , David M Paganin  4 , Grant van Riessen  1 , Patrik Vagovič  2 , Raphael de Wijn  2 , Adrian P Mancuso  1 , Brian Abbey  1
Affiliations

Shot-to-shot two-dimensional photon intensity diagnostics within megahertz pulse-trains at the European XFEL

Trey W Guest et al. J Synchrotron Radiat. .

Abstract

Characterizing the properties of X-ray free-electron laser (XFEL) sources is a critical step for optimization of performance and experiment planning. The recent availability of MHz XFELs has opened up a range of new opportunities for novel experiments but also highlighted the need for systematic measurements of the source properties. Here, MHz-enabled beam imaging diagnostics developed for the SPB/SFX instrument at the European XFEL are exploited to measure the shot-to-shot intensity statistics of X-ray pulses. The ability to record pulse-integrated two-dimensional transverse intensity measurements at multiple planes along an XFEL beamline at MHz rates yields an improved understanding of the shot-to-shot photon beam intensity variations. These variations can play a critical role, for example, in determining the outcome of single-particle imaging experiments and other experiments that are sensitive to the transverse profile of the incident beam. It is observed that shot-to-shot variations in the statistical properties of a recorded ensemble of radiant intensity distributions are sensitive to changes in electron beam current density. These changes typically occur during pulse-distribution to the instrument and are currently not accounted for by the existing suite of imaging diagnostics. Modulations of the electron beam orbit in the accelerator are observed to induce a time-dependence in the statistics of individual pulses - this is demonstrated by applying radio-frequency trajectory tilts to electron bunch-trains delivered to the instrument. We discuss how these modifications of the beam trajectory might be used to modify the statistical properties of the source and potential future applications.

Keywords: European XFEL; MHz XFEL; X-ray free-electron lasers; XFEL radiation; beam imaging; photon diagnostics; source characterization.

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Figures

Figure 1
Figure 1
European XFEL pulse structure incorporating the MHz imaging diagnostics measurement system. The schematic illustrates the relationship between the electron bunches, delivered in bunch-trains, and subsequent photon pulses and photon pulse-trains, which are recorded as two-dimensional intensity profiles after propagation.
Figure 2
Figure 2
Schematic of the MHz beam imaging diagnostics experiment using the nanofocus setup at the SPB/SFX instrument of the European XFEL.
Figure 3
Figure 3
MHz resolved transverse intensity distributions recorded downstream of the SPB/SFX focal plane for a subset of inter-train positions 1, 80 and 100 (a–c) over a single pulse train, and (e–g) integrated over all recorded pulse-trains. The train- and global-averages of the recorded pulse-profiles are given in (d) and (h), respectively.
Figure 4
Figure 4
MHz intensity diagnostics illustrating fluctuations in (a) pulse-energy, (b) magnification/demagnification, (c–d) horizontal and vertical beam displacement, averaged over all pulse-trains as a function of pulse position for the 50 pulse-per-train bunch-structure delivered at 564 kHz. Shaded regions denote ±1 standard deviation from the average measurement.
Figure 5
Figure 5
MHz intensity diagnostics illustrating fluctuations in (a) pulse-energy, (b) magnification/demagnification, (c–d) horizontal and vertical beam displacement, averaged over all pulse-trains as a function of pulse position for the 100 pulse-per-train bunch-structure delivered at 1.128 MHz. Shaded regions denote ±1 standard deviation from the average measurement.
Figure 6
Figure 6
Transverse train-averaged shot-to-shot electron bunch displacement for the perturbed and unperturbed electron-beam trajectories in each of the transverse directions: (a) horizontal, (b) vertical. Shaded regions denote ±1 standard deviation from the average measurement.
Figure 7
Figure 7
MHz intensity diagnostics depicting fluctuations in (a) magnification/demagnification and (b–c) horizontal and vertical beam displacement averaged over all pulse-trains as a function of pulse position for photon beams corresponding to the perturbed and unperturbed electron bunch train trajectories. Shaded regions denote ±1 standard deviation from the average measurement.
See this image and copyright information in PMC

References

    1. Abbey, B., Dilanian, R. A., Darmanin, C., Ryan, R. A., Putkunz, C. T., Martin, A. V., Wood, D., Streltsov, V., Jones, M. W. M., Gaffney, N., Hofmann, F., Williams, G. J., Boutet, S., Messerschmidt, M., Seibert, M. M., Williams, S., Curwood, E., Balaur, E., Peele, A. G., Nugent, K. A. & Quiney, H. M. (2016). Sci. Adv. 2, e1601186. - PMC - PubMed
    1. Abeghyan, S., Bagha-Shanjani, M., Chen, G., Englisch, U., Karabekyan, S., Li, Y., Preisskorn, F., Wolff-Fabris, F., Wuenschel, M., Yakopov, M. & Pflueger, J. (2019). J. Synchrotron Rad. 26, 302–310. - PubMed
    1. Allahgholi, A., Becker, J., Delfs, A., Dinapoli, R., Goettlicher, P., Greiffenberg, D., Henrich, B., Hirsemann, H., Kuhn, M., Klanner, R., Klyuev, A., Krueger, H., Lange, S., Laurus, T., Marras, A., Mezza, D., Mozzanica, A., Niemann, M., Poehlsen, J., Schwandt, J., Sheviakov, I., Shi, X., Smoljanin, S., Steffen, L., Sztuk-Dambietz, J., Trunk, U., Xia, Q., Zeribi, M., Zhang, J., Zimmer, M., Schmitt, B. & Graafsma, H. (2019). J. Synchrotron Rad. 26, 74–82. - PMC - PubMed
    1. Altarelli, M., Brinkmann, R., Chergui, M., Decking, W., Dobson, B., Düsterer, S., Grübel, G., Graeff, W., Graafsma, H., Hajdu, J., Marangos, J., Pflüger, J., Redlin, H., Riley, D., Robinson, I., Rossbach, J., Schwarz, A., Tiedtke, K., Tschentscher, T., Vartaniants, I., Wabnitz, H., Weise, H., Wichmann, R., Witte, K., Wolf, A., Wulff, M. & Yurkov, M. (2006). XFEL Technical Design Report, DESY 2006-097. DESY, Hamburg, Germany.
    1. Ayyer, K., Xavier, P. L., Bielecki, J., Shen, Z., Daurer, B. J., Samanta, A. K., Awel, S., Bean, R., Barty, A., Bergemann, M., Ekeberg, T., Estillore, A. D., Fangohr, H., Giewekemeyer, K., Hunter, M. S., Karnevskiy, M., Kirian, R. A., Kirkwood, H., Kim, Y., Koliyadu, J., Lange, H., Letrun, R., Lübke, J., Michelat, T., Morgan, A. J., Roth, N., Sato, T., Sikorski, M., Schulz, F., Spence, J. C. H., Vagovic, P., Wollweber, T., Worbs, L., Yefanov, O., Zhuang, Y., Maia, F. R. N. C., Horke, D. A., Küpper, J., Loh, N. D., Mancuso, A. P. & Chapman, H. N. (2021). Optica, 8, 15–23.